Patents by Inventor Akira Furukawa

Akira Furukawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10998834
    Abstract: A power conversion device is configured to output, to each of two inverters configured to invert a DC voltage output from a DC power supply to three-phase AC voltages, on/off signals for switching on and off respective semiconductor switching elements of each of the inverters so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a voltage command vector that is based on a voltage command value calculated for each of the inverters are formed.
    Type: Grant
    Filed: August 21, 2017
    Date of Patent: May 4, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa
  • Publication number: 20210114652
    Abstract: To provide a motor control device capable of reducing noise without requiring preparation of a plurality of PWM carrier waves, an offset voltage is added equally to each phase of three-phase voltage command values from an inverter to output modified three-phase voltage command values, which are compared to a PWM carrier wave to output three-phase terminal voltages to a motor, and an offset voltage is switched among n offset candidate voltages (n is a natural number of three or more) having different values at set time intervals for output to vary timings to turn on and timings to turn off the three-phase terminal voltages equally for all phases.
    Type: Application
    Filed: January 11, 2017
    Publication date: April 22, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Takayuki KIFUKU, Akira FURUKAWA
  • Patent number: 10965239
    Abstract: A power conversion device including: a first and second multi-phase inverters (MPI1,MPI2) to receive a DC voltage (Vdc) and convert into AC voltages (Vacs), when fc represents a frequency of a PWM signal output from each of the MPI1 and the MPI2, fr represents a lower limit frequency defined by noise regulation of the power conversion device, an absolute value of a differential voltage being a difference between: a first average voltage, which is an average value of first voltage commands of respective phases as command values for the Vacs of MPI1; and a second average voltage, which is an average value of second voltage commands of respective phases as command values for the Vacs of MPI2, is set equal to or less than k2·fc/fr·Vdc [V] (k2 is an odd number equal to or more than one), to reduce noise in a frequency band defined by noise regulation.
    Type: Grant
    Filed: July 3, 2017
    Date of Patent: March 30, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa
  • Publication number: 20210058018
    Abstract: A control device includes: a first power converter applying a voltage to a first winding; a second power converter applying a voltage to a second winding; a first power supply circuit supplying power to the first power converter; a second power supply circuit supplying power to the second power converter; a current command calculator; a first current controller; and a second current controller. The second power supply circuit supplies power at a voltage higher than a voltage of the first power supply circuit. The current command calculator calculates a first voltage usage state, which is an indicator value correlated with a magnitude of the output voltage of the first power converter with respect to a power supply voltage output at a time of supply of power by the first power supply circuit, and calculates the second current command based on the first voltage usage state.
    Type: Application
    Filed: March 13, 2018
    Publication date: February 25, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuya TSUCHIMOTO, Isao KEZOBO, Akira FURUKAWA
  • Publication number: 20200412285
    Abstract: A control device applies voltages to an AC rotating machine based on voltage command values on stationary coordinates. Currents in a plurality phases flowing the rotating machine are detected as detection currents. Coordinate conversion is applied to those detection currents based on any phase in the rotating machine, for generate detection currents on rotational coordinates. Voltage command values on the rotational coordinates are generated based on current command values on the rotational coordinates and the detection currents. Coordinate conversion is applied to those voltage command values based on the any phase, for generate first voltage command values on the stationary coordinates. Phases of one of the first voltage command values and generated second voltage command values on the stationary coordinates are corrected to generate the second voltage command values. One of the second and the first voltage command values are selected as the voltage command values on the stationary coordinates.
    Type: Application
    Filed: March 5, 2018
    Publication date: December 31, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventor: Akira FURUKAWA
  • Publication number: 20200400722
    Abstract: Magnetic sensors each disposed to face each of current paths for each of windings with 2n phases (n is a multiple of three) in an AC rotating machine are included, and when each of a DC component and an AC component in a d-axis sum current and a q-axis sum current obtained by performing a dq-transformation into a two-axis coordinate system on 2n detection currents on the assumption that all current amplitudes of the windings are the same is represented collectively with each of terms expressed by sine functions with different phases, each of the current paths at each of 2n current path arrangement positions is arranged to have a positional relationship where error components are reduced by cancellation among coefficients included at least in one of the term or by cancellation among values of the terms.
    Type: Application
    Filed: April 22, 2020
    Publication date: December 24, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Kenichi Akita, Daisuke Sasaki
  • Publication number: 20200400720
    Abstract: Magnetic sensors each disposed to face each of current paths for each of windings with 2n phases (n is a multiple of three) in an AC rotating machine are included, and when each of a DC component and an AC component in a d-axis sum current and a q-axis sum current obtained by performing a dq-transformation into a two-axis coordinate system on 2n detection currents on the assumption that all current amplitudes of the windings are the same is represented collectively with each of terms expressed by sine functions with different phases to one another, each of the current paths at each of 2n current path arrangement positions is arranged to have a positional relationship where error components are reduced by cancellation among coefficients included at least in one of the terms or by cancellation among values of the terms.
    Type: Application
    Filed: April 22, 2020
    Publication date: December 24, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Kenichi AKITA, Daisuke SASAKI
  • Patent number: 10871365
    Abstract: Included are: a sensor magnet which rotates integrally with a rotating shaft centering on the rotating shaft, and generates a magnetic field for angle detection which is for detecting the angle of rotation; a first sensor and a second sensor each of which is arranged opposite to the sensor magnet at a position separated in angle by 90 degrees on the circumference centered on the rotating shaft, and outputs a signal corresponding to the magnetic field for angle detection; and an angle calculator that calculates a rotation angle by using the signals from the first sensor and the second sensor.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: December 22, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Yu Kawano, Yuji Takizawa
  • Publication number: 20200373869
    Abstract: A power conversion device is configured to output on/off signals for switching on and off respective semiconductor switching elements of an inverter configured to invert a DC voltage output from a DC power supply into three-phase AC voltages so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a current vector that is based on currents supplied as a result of output of the three-phase AC voltages from the inverter are formed.
    Type: Application
    Filed: August 21, 2017
    Publication date: November 26, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA
  • Patent number: 10836423
    Abstract: In an electric power steering device including a controller, which is configured to carry out feedback control for a motor including independent two coil winding groups and being configured to rotate a steering mechanism of a vehicle, when one of the two groups recovers from a failure that has occurred in the one group while control is continued solely by another group due to the failure, the controller resumes cooperative control by the two groups, and when starting the cooperative control, sets target current values of the one group and the another group to values different from a final target current value based on an actual current value or a target current value of the another group at a time of the recovery, to thereby output respective control amounts for the cooperative control.
    Type: Grant
    Filed: October 22, 2015
    Date of Patent: November 17, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Akihiko Mori, Eiji Iwami
  • Patent number: 10797620
    Abstract: A control unit includes: control command generation means for generating a first control command and a second control command that specifies currents to flow through a first winding set and second winding set respectively; voltage calculation means for calculating a first voltage command from the first control command and calculating a second voltage command from the second control command; and first voltage application means and second voltage application means for applying voltages to the first winding set and the second winding set of a rotating machine on the basis of the first voltage command and the second voltage command, wherein discharge control for electric charge of a smoothing capacitor is performed while torque generated by current flowing from the smoothing capacitor to the first winding set and torque generated by current flowing from the capacitor to the second winding set are cancelled out with each other.
    Type: Grant
    Filed: August 24, 2016
    Date of Patent: October 6, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Munenori Yamamoto
  • Patent number: 10788319
    Abstract: Provided is an angle detection device including: a correction signal calculator configured to generate corrected signals from a sine signal and a cosine signal acquired from an angle detector; and an angle calculator configured to calculate an angle signal for a rotary machine from the corrected signals. When one of the sine signal and the cosine signal is defined as a first detection signal, and another one thereof is defined as a second detection signal, the correction signal calculator calculates a corrected first detection signal and a corrected second detection signal, and the angle calculator calculates the angle signal for the rotary machine from the corrected first detection signal and the corrected second detection signal.
    Type: Grant
    Filed: October 3, 2016
    Date of Patent: September 29, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Wataru Ozaki, Yu Kawano
  • Publication number: 20200300601
    Abstract: An angle detection device including: an angle sensor AGSE outputting first and second sine wave signals SINWS1, SINWS2 having phases that are different from each other by 90 degrees in accordance with rotation of a detection target; an angle calculator calculating an angle signal corresponding to a rotation angle of the detection target based on SINWS1 and SINWS2; and an angle sensor AGSE abnormality determiner ASAD determining an abnormality of AGSE based on SINWS1 and SINWS2. The ASAD includes: an amplitude signal calculator calculating an amplitude signal MALS based on a square root of a sum of squares of SINWS1 and SINWS2; a first angle signal ANGS1 calculation processor calculating ANGS1 based on SINWS1 and MALS; a second angle signal ANGS2 calculation processor calculating ANGS2 based on SINWS2 and MALS; and an abnormality determination processor determining the abnormality of AGSE based on an error between ANGS1 and ANGS2.
    Type: Application
    Filed: April 28, 2016
    Publication date: September 24, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Isao KEZOBO, Munenori YAMAMOTO, Akira FURUKAWA
  • Publication number: 20200300671
    Abstract: Provided are a failure determination device and method for a rotating machine control device, which are capable of detecting failure of a sensor configured to detect a rotational position of a rotating machine while the rotating machine is in operation. A rotation angle estimator calculates a rotation angle estimation value. A relationship between the rotation angle estimation value (?est), and a first angle detection value (?1) and a second angle detection value (?2), which are obtained from output signals of angle sensors configured to detect a rotational position of a rotating machine, is monitored while the rotating machine is in operation. In this manner, failure of the angle sensors, which are configured to detect the rotational position of the rotating machine, can be always detected even while the rotating machine is in operation.
    Type: Application
    Filed: April 28, 2016
    Publication date: September 24, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Isao KEZOBO, Munenori YAMAMOTO, Akira FURUKAWA
  • Publication number: 20200255067
    Abstract: To provide a motor controller and an electric power steering apparatus which can suppress torque fluctuation resulting from low detection resolution of angle, with simple calculation, even in condition where the rotational speed of motor is low. A motor controller estimates an angle error correlation value correlated with the angle detection error based on the current command value when a change frequency of the angle detection value is lower than a cutoff frequency of feedback control system which controls a rotation state; corrects the current command value or the angle detection value based on the estimation value of angle error correlation value; and changes the estimation value of angle error correlation value so that the absolute value of angle detection error increases with respect to increase in the current command value, and the absolute value of angle detection error decreases with respect to decrease in the current command value.
    Type: Application
    Filed: November 7, 2017
    Publication date: August 13, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenta TANAKA, Isao KEZOBO, Akira FURUKAWA, Seiji SAWADA
  • Patent number: 10720873
    Abstract: Provided is an electric drive device which controls a current supplied to coils during normal operation so as to be less than a current limit value when normal, which is determined from heat generating properties and heat radiating properties of a thermally coupled body that includes the coils and an inverter circuit. When an abnormality in each group or each phase of the coils and the inverter circuit is detected, the supply of current to all phases of a group suffering an abnormality in the coils, or to a phase that is not capable of continuous operation, is stopped or reduced; and the limit value of the current supplied to a coil that is capable of continuous operation is reset to a current limit value in the event of abnormality, which is larger than the current limit value when normal, within the range of improvement of the heat generating properties of the thermally coupled body due to the stopping or reduction of the supply of current.
    Type: Grant
    Filed: February 23, 2015
    Date of Patent: July 21, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Yu Kawano
  • Publication number: 20200220488
    Abstract: A power conversion device including: a first and second multi-phase inverters (MPI1,MPI2) to receive a DC voltage (Vdc) and convert into AC voltages (Vacs), when fc represents a frequency of a PWM signal output from each of the MPI1 and the MPI2, fr represents a lower limit frequency defined by noise regulation of the power conversion device, an absolute value of a differential voltage being a difference between: a first average voltage, which is an average value of first voltage commands of respective phases as command values for the Vacs of MPI1; and a second average voltage, which is an average value of second voltage commands of respective phases as command values for the Vacs of MPI2, is set equal to or less than k2·fc/fr·Vdc [V] (k2 is an odd number equal to or more than one), to reduce noise in a frequency band defined by noise regulation.
    Type: Application
    Filed: July 3, 2017
    Publication date: July 9, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA
  • Publication number: 20200177102
    Abstract: A power conversion device is configured to output, to each of two inverters configured to invert a DC voltage output from a DC power supply to three-phase AC voltages, on/off signals for switching on and off respective semiconductor switching elements of each of the inverters so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a voltage command vector that is based on a voltage command value calculated for each of the inverters are formed.
    Type: Application
    Filed: August 21, 2017
    Publication date: June 4, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA
  • Patent number: 10666170
    Abstract: A failure determination device for an angle detector for a rotating machine, including: an angle detector, which includes n pole pairs (n>m), and outputs sine and cosine wave-signals in accordance with a rotational position of a rotating machine including a multi-phase winding and m pole pairs (m?2); and a failure determiner for detecting failure of the detector based on signals from the detector. The detector outputs first and second sine-wave-signals having 180° phases different, and first and second cosine-wave-signals having 180° phases different. The failure determiner determines malfunction of the detector when the failure is determined with use of at least one of: failure determination using a sum of the first and second sine-wave-signals and a sum of the first and second cosine-wave-signals; or failure determination using a sum of squares or a square root of a sum of squares of the sine-wave-signal and the cosine-wave-signal.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: May 26, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Yu Kawano, Munenori Yamamoto
  • Patent number: 10666163
    Abstract: Voltage commands of respective phases are substantially equally shifted in such a way that a maximum-phase voltage command coincides with the maximum value of a PWM carrier signal and are compared with the PWM carrier signal, so that a voltage is controlled; in addition to that, a current detection value corresponding to the phase where the lower-arm switching device is turned on is corrected based on a current detection value corresponding to the phase where the upper-arm switching device is turned on.
    Type: Grant
    Filed: June 22, 2016
    Date of Patent: May 26, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa